SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecea80aedac864bca989001f42fada0c78b854c3c6fb6be82efc0d4d8af0ea07' 
  AND token = 'N3lYBZP9InLjpgFL30PhxcX863mXMZsZqo5+bTmld/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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