Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c584165ca4a736a7768782bf45b50daa06f7d5bf96ca45bb5d3a588a089df139' 
  AND token = '04/QboRBYNx0xYz3MxzCsMgGauW5b14eI+XW75pjiy4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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