SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e92764d1d67f1f3af10f2e1ffe171b5209300da5c04cc749d105a87d58e2dfc6' 
  AND token = 'tAR/479t7rIR94u8nRFC6YubaZP7lNh7rCsa5Txt4xk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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