SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3fa0910ab3317f24d367dc6923366f20c857967b0c3d635f9dc393441c251765' 
  AND token = '7BzjYvZo81Yd4AhG0oD7LBhmJPQhWTG/uBwv4dSk9J4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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