Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3b373e8972dfd60c9640d423d1661688e19d852e5788dd3af0c3d371bbda8a7' 
  AND token = 'HgpGfisLDudvoVXXI6UHDQMVbvkvv+NHqoCm3j/HD8s=' 
  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"
    }
  }
}