SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e362a869b1a11bc1b9af1c3cd36ac47de31aba4c19dc1706ffb81e6794832607' 
  AND token = 'xWI7ngYw3olBpIzhsnFXX0aCRETTwMrlidrncqQ7zYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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