SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0fa5a11719eb590ff82190212bf001d77e403527cb3ea186944929523d46fd53' 
  AND token = 'gmjS79XJAehYTdOL06gGx5TFJzg3KxR+VaWou99oSbQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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