SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5dab7364d78df307ea618526b7d9276c3f73317002d849eee7569fda219f8cdc' 
  AND token = 'ALK4YNEO/WXUlocoEjDspVRphQmSNqO+wG8NjyJ5FKc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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