SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c1662e99557aecda3ea82cc98fe6746488264931078bf9b9bfbb0f20398af62' 
  AND token = 'dQ3Gi4YcpAnBqg81qIiwLzaUTETTxZaaGyD0hwzDZl0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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