SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcffc5fdd7b0cf5707328394d3d01406d9fa4eb8769f3f386deae561de15b42a' 
  AND token = 'SvxuuQgdE9VBts26wjdmToqUj4YhXpnvDQ20To/YOg0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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