SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4627e146e22dc86cd30eed2fe98104377747177878bcd31e46ec2734a9a46ac9' 
  AND token = 'v2D2HMxUAtAZFgyDduGbm7InUwI/sHeM/nYvIhbgf8s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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