SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db2bdf845c6efe59f1ce7f4dc2e367c42ab822cb08fbf6c2a409c5281321b25d' 
  AND token = '/8PYtajSEvz+FhB5mQJGRHsl/PjViEbnudx5AfuxXH4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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