SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b10baeade020c7496a3c358ea7f241f56756288eef0afec8efb3ca53f73b12e' 
  AND token = 'uo62RoGTiSqdLInUBVO88A7cTlIqmPi9QJxWzXUdQh8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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