SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b1e3a50b8c6c902fc99c632001467f17eef5bf47576e137495df2806901b1b4e' 
  AND token = 'pmJJHkWn0R+sAIWvAarPcbY0lqogrC9xybP1oiF9PGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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