SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb9d0b7699f338c226b8b34151db9304fbeff065ab80b871f7b46576e01d2e52' 
  AND token = 'oE5NDEvuIa64YIKHp6hlinR0Obn1hmA972b5oqRVaQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}