SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '799a757d7587646bfdc066cfda6dd524b97c29a2fe76a5882f8019b04c1c6fa2' 
  AND token = 'TNNkQ+4YvgVYkMydMcUuIcou+xCilWT27fpYd4JqX08=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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