SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09897388958fe22694e7d79651ab26b6a53ecfa4fc1734dfda3bc3fefe9bc091' 
  AND token = 'j9iaWIdkRMV/vhIQu4m8wg/GNIT4vGeScs70ZlMKiaE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}