SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dae8a8fd660c74cf1360af496148d71e7f0b04e88bce242c03ac0dca6d45a9b1' 
  AND token = 'DBCWx7XfZ0jTu5YlPSx75nGabl+ztRgCkTtPAfTZTYc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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