SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f490f5a11814d64945efd0918bf3a932c671313b2d6ba15474c24c0bc519f6d' 
  AND token = 'lorLtgNWh8Y7EUPEmQ5yW5ceKc/o6GMQFYqHrDIowhM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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