SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ad9da5873f139940abeb3d63c9a38125cc1338447132deff43eaf5a261d1f59e' 
  AND token = 'DU5DgILsPDjU/S4RMQEYrosBHP7YR6+/mp+eNKwAo+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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