SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e79c8cbdf2f719a6e7d14005e718f518203f118abc595ef469615409969a8c2' 
  AND token = 'vsurxMhoThkLqnEmmKGfiwDbLotYPEfB9/4wKBbZFO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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