SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afadc0ebe819c8d9f490b90f3673104468a41cf2f75c887e60c6b599306840f4' 
  AND token = 'PkjJvIPCcp4hI8pYYB6upKWz4M9jAcgj85S7clTmRuw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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