SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c2c8a8b34d9c5216c96d7c2c38664dd91fd61965ff4c9dac663c41ccc04799a' 
  AND token = 'phPFH3uUHz2QuJXzNJNJ/jlxZT3Of2XRdBdaLTUVUOo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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