SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6143389437ce32199b15732c4f22d285d478704b41bf04cfc2861c89604b800b' 
  AND token = 'o4dZcoQavpOAIp7q2WP3mtb4h64Ri+tU0VcQcSor5r4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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