SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba8df735d7f58aeff0fc25a35f110a20483db038ca9d9c9741f553bf14e2132b' 
  AND token = 'z3uvKD2k1C8oKzm6iPBkYHD+oxdkXLHKroETQUT4cJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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