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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7fed6e678868c0f39b97278a5b8b08766d6d8bbe8b46ad6343d4dac4cb1892d' 
  AND token = 'WsGmlJ2CVkS+m9bVzRYUWgHYdCSnEaz0caRGI94utuw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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