SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29adb1b5ebceb95206300f61230dcdc4ba41335d9fd414161224335478c7706b' 
  AND token = 'BG8fVQVJSDJ9PaXdwaJeTzjSDn0y+JDgeLh6ZMUvMNA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}