SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f1a549d4d09eb74720db2c3268d5157ea1798063af6617975b7a973b4d1af7e' 
  AND token = 'mdGdSpdYoodp/7xG4g9en33+JzAv/ZZn4T3B/wQR2hk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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