SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6f2402b39a52bf6156446670a69d6839b0b77a5c3fda4bfd11362f71ec8eb5d' 
  AND token = 'M5aD1flXusqMZwP7c4RSrZl4ZmvU+feDV/pGzq1HVLk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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