SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65407835326532af1d220833f91c5a7b2f20a36afc0177dfee0b98b33d1a9d45' 
  AND token = 'dwARr3SNv6Z8LI+OA3qBSZV0boSYyJoSL7m6/HSKYGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}