SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '965ba49409309a29136a0bf0047033fd7721e981029d3806617250b70ab19157' 
  AND token = '6PH4dJ9pAt8H6SYYAweivhSksexiATExPVMbcoMLtUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}