SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '352df444ca7431078c38d909813b1b0ddfa86714413b3f5fc138f83762608560' 
  AND token = 'CbwIkz3FZIdGyl/v97wk7jG1SvWs0Y1VgmXhIio82nU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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