SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d6457ded92e92954e2a73155799696c9bfa779867259ab70203dbaa836cbd4e' 
  AND token = 'G5OeJqpJ5TV2fReKHp0YtSZ154IrBv/7iFQGOYtR3FM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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