SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd983b265f6e7a65b2baf616f802a06e6a961db0b4a74632bd225cf6decdff5f4' 
  AND token = 'jO/yqQ1dlKrVJ4ppiTZWzH1DyI9hPTwijUlsYgX3DNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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