SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5a390dea29a01c67d39ae706c51cfb96021ff373d7d1ff90430a5e517a9d37d2' 
  AND token = '0ZwGhHRXmyjjCnfiNPSUajCwj2pUpDrCjunSwLU7QNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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