SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '58d062808b7b3ce136465c6d1711c48908aefd0aacbac10bd0846e628fc93614' 
  AND token = 'YP6xm+kqc8MsM26Vbix2RKhsz/jsPUxsWJPPkeNmX+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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