SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3bbf27462954c89ec0f620aaaa9da704b186b788f0fd7ae7fce5f5b29c05c05' 
  AND token = 'DhvOwkOu1lMJg832b6gSrtqGRLZYt1hIDDj3hpte4E4=' 
  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"
    }
  }
}