SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ed9dc563277904742186270f89b62c8de2f0647f21d0bf9bf0593e1be8a71e46' 
  AND token = 'JEoKe1J01KXmN9UC706wyDPFRgSVSG1Bq5iAxXgHihs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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