SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a03205d193f054c18c257c0101f0c5b77aad537db0986eed464a8b734ffc4935' 
  AND token = 'pBxncBynbIWUZohVez8ybo9sA1SOWdACh209kzJgQO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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