SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7b2b9e0ec8b77a89253e9d1a1ad43621253b053d57d48ae0198f744cd09784d' 
  AND token = '/PE+3Bjvc8B9SYoKj1zFeLJbLzCNlX7gKRGoClJRPUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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