SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61c6f97a87511873c0049923f8a4c7168eae35fe2a1562d02bc51b4f3a477e5c' 
  AND token = 'Z/+b8W6voBYS4jQ7ONzDdp5c0lxLD/DUlvXv3BHGG6A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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