SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8732ac802e2f523a5e13a27ea02114207b1484453354101d3d1ee6d3fd4a67b3' 
  AND token = 'Q0mIUBExYnJac+XqA8zDm9rmClBd6PJFLO1zzTS1inc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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