SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1bd13311555cce91757f1de5fdee874c024e24203b7be664a821ff4d3b7ae00' 
  AND token = 'T/WIOwRxOSrzLfa1X53jIcUSIqfFpPjMdz03zrPK/0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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