SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4be47f695f6552f427821c0aed42e53c862aa565c94dc196cbd336391d6c378f' 
  AND token = 'ylVXcai5hYzXcevqH66zDshC8BTOr0jMHcFpvYPPxkg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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