SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe29bdd0d383b993243c9e2fdf192b7678d210909aac4a195464ea735c8e14d6' 
  AND token = 'Y2QRugBdEDNyNpwqiq7NR5r9G5mcnkArUyF6MHq15Xw=' 
  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"
    }
  }
}