SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bff08947a0bf81ecbeefed5273b5f4ec41ce9359421b12b30a78f6912515fabb' 
  AND token = 'YhHiC+OaDOeMEwoL/JlXk8l3kQcKkNVChGjeqLFqBqc=' 
  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"
    }
  }
}