SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '72ec2c09bdebbef24666cbbf0dbb9c513b63986b08a56b40ef94daca8404aa37' 
  AND token = 'M4d5xHpJv+r1QZm7oWc/vM/DJWazTsioDm4Ksvd3N2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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