SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a8ac16bd501e1f2c9bcfad3bf6e14023e0fb54ac47da6aa71791f14ace3b28fe' 
  AND token = 'rZgWIZ1D8sh5ucMllNfxnFGinwAtJYRb+refvQ9kLYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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