SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d6c5b5f6b4aa5acddcdf826ee230f45e948a2a5f0834cf616f86794aff509dc' 
  AND token = 'WIqpgfz4elNQRIAy4j/tHJBPAdQLaHOP7bNNpNSV3tI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}