SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd3e3e8326599fce9f26112e925d335a0db37b09ee42de4a4ebdaa8ba64bb5c34' 
  AND token = 'xkvP3OEFGTDCUNYPQIqWOUSGHAmt3b3E9RIQjIT4MtI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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