SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de7c676c1fc390d61da2cd1cb428eb6ec0dd9df1514c4146a0c84de917e19365' 
  AND token = 'oUsuvi7OrBDJGw5BzS9SVyB061jRCS91HTraS8T3Vsk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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