SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d7f88b137f4eafc7219425eebc9f1da7fa3445edf47c7b5d0c206af33cc1235' 
  AND token = '9lKF2uqhdg6b09ZzCkrBLETwz2nQeoY2w4Sl/I+V0dw=' 
  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"
    }
  }
}