SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75d871b71a947c3e8ea98da51ebf8bc94a706ef4a80d78ff48539933b9d7f27c' 
  AND token = 'lBV0uxYlYCgZ8LhH60FyPhLh6g3sItzuAvSwrbKzeDA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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