SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3aa80240bc54eaf9e17153228931344c76d09aeec44f3a407fef282c4d80d617' 
  AND token = 'xSjLeziqU6/ta2CZx1tqXdfYdtULyB54pryZIQW8vc4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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