SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ea547f005c1ecdbfba249e5a22591881530d8a8b6d04d86b1ac3dbdb207e75e' 
  AND token = '6vAPK8ji5P1WrC1eui89plcSeqqyNt1CvjOoMgeICF0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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