SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aab735c99d4f278d5d21e6b4cf214d05812f7bd7716cb4bec67bf6ff8543d4cc' 
  AND token = 'CJw/JMKUrP2go3Hjm1t3TAhpPLfCqjSi+SZMcsBOEGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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