SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0a11274cfee00ef1e1fe3ba45dad17d49af5a22aec7f10da952ced9ab661406' 
  AND token = 'muEG2MMhQ2UHr3T8j+3ghu9Te7XlVrjM9/HWb6A1Aic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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