SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f4d32ed739ca855a42f83d4858efe6376d608643673c67d06413589c6d8bd60' 
  AND token = '/IctQJgWhHjILy6Hmxni+Bqb+UYROOPyfeYZKbA2DGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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