SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09d48a27f50b3e0541c6cad0a22a6ed92379954e946f47d16ed914900349eeaa' 
  AND token = 'eFhbjeLWUxvPbDW6wmu4vgfbppjtexhPS0/1a8SJ8Xg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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