SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0bf55a62a3c30b1d7301414038f721bccad48aa402dd64ec8f331029c58da72' 
  AND token = 'cj8tOQNEJ6f0kTBT6bxEbr6fVY31uoAG9aoFHegBCxw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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