SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '968887b60d3828c37ad3fccd357a76dce2344479ad0e181e5ba0c669fadf9d63' 
  AND token = 'XqemN2wN5Yogef5NmZWLBfAiOXAL4rs+bUyx5qn1KZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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