SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b212d18881d8755fd465e89d874799a12f8053ad02ce376fba225b4de8bf7f03' 
  AND token = 'o/iB3ISLNYEFVjTMYP4Z9J+HQOoWx0isSOQcU+Qyc3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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