SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57d827e883101be4db10ae9229ffe4f3d489e652d29322779b3d894b17c99b04' 
  AND token = 'LdwEa9iaK2pSiifcHNhuS3nooammF0+pNT6RJlDB7jc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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