SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9083da20dab4924832a62d78795bfa15d24eb022482913362711c360e56eaaf' 
  AND token = 't4mFefy35nhn/0jumRLWqB5thrDSorlq8ZmytqiQqDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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