SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74f95b5fae0f6da8b617e4d1198b8548e4f3d599882825414a981b02177b62d3' 
  AND token = 'lJGwh2yGmwJ8jq5yuU+ymcMSRnaqKz6dha0/EmAFuqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00065

JSON explain

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