SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5924e6d189c22e7118c5af4ad814ecb9e9c5d1c520cec6fd22843a6975c13fa4' 
  AND token = 'vwyHKKBF0+oO/ZAR9pIf1/vC8rdzsENr++dB4HU1oFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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