SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6de0d45b0901ed9145bff623c51a9a0c2b747833463b658511395037bc2bfac7' 
  AND token = 'HCKNkPhD2mxmLO9R9uQ4gVlhazBEOMvz2iXeJ/06DOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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