SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8337db9aef335b6cda020d8dbd2ba74691590048653ab229e164998b02614d3' 
  AND token = 'RjMbDumRZOZzfRbA8P0D1NcPdEWdL2qXIqkVSHwR9g8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00252

JSON explain

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