SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '570db08924d92e2ed1dc1cfdff6e518825a893032b05b59768438188c0d91676' 
  AND token = 'bFFeZwWvoHPIW5mmi/kG8a7YoDTIkyhdz6adSdfbM9k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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