SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83f852872f3b287d1134f38689e61ab1801f62daf86b45de473c529c1ceaecc6' 
  AND token = 'ugxngaHVchHC5M+YgHDJg+rA4i+2XFGe+Q/yNReJxNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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