SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6ab98f19ec4d41042a499991023b16ca3230239537f7781083c36719795fa68f' 
  AND token = 't26ZmQzIJ21oGrZrvVcf8XVZEClecb/JZc1gdSoL7dE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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