SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '506acfe59b7e3a8b61a39b9ca38a775b24d516e959ebdd6f2b88d15b00d57f8d' 
  AND token = 'R+L46IzG87ZOhDUZ2Rrl3SzL7SelAXBJqEG0ZVxvNNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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