SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c519aee27098700c61658bb6d9af80a7db8ba46f2f29434fc4db9a504734c33a' 
  AND token = 'ypY4sYUgqvLs71/qtRtBIbMAFBcVumgiuIOuS2T4Jks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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