SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '962150a018f2da02b81ef6c908efe979d3db58cefbf492aebd33f54c4ef5dd44' 
  AND token = 'uif86X3UNSe0CLBxVpfB3yvI+/TTnMMzVwd9qMDBRUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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