SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '00aca306796017319dce07a3514f7f3d3e8755cb2b075b410ac9030d64d21f6e' 
  AND token = 'LzTkm2dFgtuHYJXIIpI4GWSyYJTIUd7uOVlfQC8zSOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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