SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1338c338f73a291b34f325cf8301af8e87dcab180b930a4ccd36d08cd79fa6d' 
  AND token = 'QKoFbJYGm/FIcefgivQc+46gLGViMGlSz8qOJPZEFXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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