SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29a5add7c7adce13cadac430f5781e0a2d5e3b02aae4c58bfdb75cd9c3d83289' 
  AND token = 'Zh/C8YnamRzdmNjnOlWwFhgJCadj+VZWwFPFgy9zEGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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