SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba1cd22831f40f94ddb27dd1a904455ee8a1d9a21252c2e1cb0ea38dacdfb9e3' 
  AND token = 'mLsH1oIB+ggD2iUkTQ2koIfd6RWWC6uWWU/ND7xCWAs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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