SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ead33b94ce30113dcfde85266779187709d015f8ab5e629534d37ef55ef0494' 
  AND token = 'R0r2pLPc+WfmaxmMJoqODtjeRW9i6zGcTcOHmnOzfw8=' 
  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"
    }
  }
}