SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5a45dd4c6a85e8d42e350e48254e9ea88e1057e5a736d77028f63cadd309ed92' 
  AND token = 'skiDxHBPMEGaaF0awXHpJSSPjSmB/POmHa1+3I2nPZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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