SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'bbfa0673441a4ce5887ecf92136bf3f71337137cf125fbc0e3176799cf1414be' 
  AND token = 'EbNpZqWNPgMDQBmYK7UsqjNm1dan50zDJBrm1SlITyQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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