SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77d7f39d4a6278276a648f012b6aabbd37f79efe52c19eccd389d89479728015' 
  AND token = 'yt/jbNUjJTIWGupZ217yJwbQWMUXPfig49so+evnVh0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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