SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4726bb5416c1be7315b08697f29532e3744bb6e3e01012e7cab57666f3e92b40' 
  AND token = 'EckEXwQgzGLBCfw9wjWWT3VI4XWhJy94cLTBeMf/xeA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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