SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3c027399446a6ea847afa8208557a4347139923c25bce1d5569fb1e567c0b4d2' 
  AND token = 'X7juFuJLY8bzRDCxHwVsMAOULPeGn40x7N8agi4npMI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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