SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c3c564d98c52683b03c6dae308a2a533fe08dcd58209649d3fa8fa9b2e73135' 
  AND token = 'Mf0mLhXwCd+6U+Ic/WdlT2OPSOe95/Toou+d1/CXQ4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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