SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8acec75a64f0abc59c3011ca7e8b28df6a05385fea9e15807445c0d223650045' 
  AND token = 'Ob2Qo0to16vtChlGfaopdMCYDiWDdSjVKa3PYn+yXyc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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