SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '420217dcf5f8b0d3f85cc31bf63fc13bdc6033a036a3e89873dd4e64137689b5' 
  AND token = 'RLQSAKXrU+ZR1qr9FsgtkX/HooBo+ypvLq9smGY0hqM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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