SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '937a138dc8a791d237381d1d31f24c45ef180452ee58217e906f53dff41d6b6a' 
  AND token = 'pwu5ZmMVgetSVvIjOwzRR15pJskt4M8pJPbJOH79zS0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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