SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea7b8b8280f1cf7a0656b4af64616d022576e312fc710832b6494a7a4edc7ebd' 
  AND token = 'tYvGHaijuSyCb/+x5+hX2Zpw5PCt7t4OUy3NSW3sDlg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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