SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c299567253a8e76448f9520cca2ccb600d8d6c86a14c961a935f2f8ab6e79152' 
  AND token = 'cJvAYELD/vqDPb5gOH/BTWJBABxs3L7FXbAhzLV4Gi4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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