SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3aca720266cf9755ca6049e2c06d888e789e757062909c9483cf6a34e423c9d6' 
  AND token = 'jCGZGRxfbGYzOQ48+PVSxzuEAvZHeljsQYG/Mh++gUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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