SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a454c2cfdc4c097318352e64e6bdfd0c913cf9d55dc7dfedd80ba3a752e9c29b' 
  AND token = 'e5cgQtL3MXAPOeStx1SCBPYLqBjENveBfCFqDh6uB90=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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