SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9caec7654ab5e750c2297ab0c42181dff5380eb20b921a05f8afd1d43bf06815' 
  AND token = 'UY2Lbh1lQnmyCyRzdFmKqFvz49+eLQVuC2852/M2jYM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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