SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7edca4d97fa05c1ef7c4441a5c31911bdd5266a6538fd78e47af3679b564334f' 
  AND token = '3mYqtSLzbzpPtZB6UoYn9KoYxWyhbKAYeBpsff2Yjlk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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