SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48aa87cfb6fc24183460239e2d8b55cbc6b228453dcd4e12d5664c664da44bca' 
  AND token = 'OKSguTSL4KZf9TISRRSxcgLvqaNCP2JIGEsR1RRpUnA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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