SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5467b4d759ba584cf0aaf1a26f3e423e2f87639e2b80bc4bd21b6f5c961a788d' 
  AND token = 'yCYk4Vc1YmXvT4nhT7FpweZ1+WSPfrLLGgv/Vwxzf/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}