SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0dc3e6da7573b6adf9cea933d18f2d90bb5dc9bf34ea32a24ad3ed6da4ed0ac' 
  AND token = 'AdoSzsvjqxrPkwrIPMRLQRESXYuxuNgKQ2yNpRBIA9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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