SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0833b6b201f79be2ad0b0c58e46d12286edd694bbabdcae1deaccec69920163d' 
  AND token = 'EbWzDgCDsLqkP5s8Ai3dO/dXbz4UWhjXiaeGxYg/BjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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