SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b13362c3a3ec6cd0a4e5852796693b4a6ff0e43daeeb2af7626d8ac90356951' 
  AND token = 'rzqu0Bzmq8X4ollJ/54YA0sTqPjIdNi2Ey1WnrUkqbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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