SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5aeac056dc0c461ecce393b7d3a327be9669bad76a26b8b74e1c085634ce905' 
  AND token = 'zplAzuUzSFhgzG2iGuVItfNaJINSZOvOPGYU3GgM2Nk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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