SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b39a060cb56fa72ad19c5c97af63a72b1aaa82e37be28997cedefe3a328ea2ce' 
  AND token = 'DWHG0Lrw2uLj67hLNCDI28utQ+oX8auiUkdnUBhshFA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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