SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be157c02a257ebb3ad4ddfe6c9acc19430486e9b0ea87046e648093294baeafc' 
  AND token = 'Su3Hd1JAiT3CDYP0h0mvIT9QLX+LIVeni+1JnNQRvOk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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