SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '30266355df4d5ae10afaefcca75a8ab4c8ae39cad04b612c40361cfb342df042' 
  AND token = 'zlo9T5KYjDle97M34cmawHbtlBjatnkk6nvHtt+qYHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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