SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b9ad6c22676e127631843772b8c5b0356f0a02497a563e2487d9121516bd32c' 
  AND token = 'XTME/4kz36jRj9x2mOx7EAVwRJNg+Rf/yPr4+1gzPOk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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